The revival of the UN Security Council’s regulatory powers after the end of the Cold War as well as new challenges to international peace and security have led to the development and diversification of UN operational tools. In the absence of United Nations’ own material capacities to undertake necessary military action, due to the non-conclusion of agreements provided for in Article 43 of the UN Charter by which UN Member States would commit to provide the necessary force and other assistance to the Security Council upon its call, the latter developed other means. Today, there co-exist two mandated operations by the Security Council vested with the power to use force, each however within a different scope, limits and objective: UN-led “Blue Helmets” and UN-authorized military operations. This functional rapprochement causes nevertheless a great confusion, both in practice and recently in the judicial sphere. Hence, the clarification of the legal regime of each is essential. While the UN-led Blue Helmets vested with the limited power to use force represent the new generation of peacekeeping operations, the UN-authorized operations constitute a decentralized execution of the Council’s enforcement measure. In the latter case the Security Council turns to UN Member States or regional organizations and delegates them its exclusive power to use force under Article 42 of the UN Charter to execute it under set conditions. The limitation of the use of force by the UN-led operation to the strict defence of its civilian mandate does not exempt it from the regime of coercion established under Chapter VII of the UN Charter either. This raises a question of the legal status of this UN-led operation and whether possibly such tool approaches the original concept of UN enforcement forces laid down in Article 43. Analysis of the converging and diverging elements of both operations shows the complexity of this operational domain, the clarification of which is proposed in this article via a legal perspective.